On the Other Hand
by Lawbreaker13
Summary: On Marinette's eighteenth birthday, she finds out the last names of two important people in her life, her soulmate and her mortal enemy. There's only one problem: it's the same name. Soulmate AU.


Inspired by a post by squishychatnoir on tumblr that read:

 _That soulmate au where you have the name of your soulmate on one wrist and the name of your enemy on the other wrist but it's last names and Marinette has Agreste on  
both wrists  
Also Adrien has his own last name on one of his wrists and like the angel he is instead of doubting his father for a second his mind immediately jumps to "I am my own  
worst enemy"_

So...yeah props to her!

Enjoy! ^_^

* * *

Marinette sat solemnly on her bed, legs crossed, hands in her lap, holding the ends of her blazer in between her fingers and her palms. She stared blankly at her neatly tucked in comforter showing no signs of emotion other than her wide eyes in...was it fear? Tikki had been looking on since the moment Marinette sat down, worried and confused, hoping she might say something at some point. She never did, so Tikki took some initiative. She floated over to her holder.

"Marinette? Are you ok? You haven't moved since you got out of the shower."

No response. Tikki floated closer.

"Marinette?"

Nothing.

" _Marinette!_ " Tikki was up in her face, gabbing her nose. Marinette jumped a little.

"Wha?! Oh, I'm sorry Tikki. I'm just a little...stressed out I guess," she said with a sigh, anxiously tugging on her blazer sleeves again. Tikki cocked her head.

"But Marinette, it's your eighteenth birthday! You're graduating Lyceé tomorrow! What could you possibly be so stressed about?"

Marinette sighed and looked at her kwami. It was Tikki. She could talk to Tikki.

"Okay."

Marinette looked down as she took her blazer off, keeping the inside of her arms facing downwards. She looked back at Tikki.

"Here's the thing. When I was getting out of the shower this morning I...I noticed something. You know how when humans turn eighteen they find out the last name of their soulmate?"

"Of course!" Tikki said, fully aware that Ladybug and Chat Noir have been soulmates throughout time. "It's very exciting, isn't it?"

"Yeah..." Marinette replied blankly. "Well...here's the thing..." She flipped over her left wrist to reveal a very familiar last name. In small, delicate handwriting very similar to her own, Marinette's wrist read off the word _'Agreste'_ in bright red lettering. Tikki smiled widely.

"That's wonderful, Marinette! But I don't understand. That's Adrien's last name. Why aren't you more excited?"

Marinette sighed. "Well, because...we also find out the last name of our enemy. And honestly, I kind of expected it to say _'Bourgeois'_ or something. But uh..."

Marinette slowly turned over her right wrist. In the same place as the left, in the same handwriting, but this time in black, was a nearly identical marking. _'Agreste'_ read proudly and boldly from both of her arms, the severity of it slowly sinking in to Tikki's mind. Though she wasn't quite sure what to think.

"Huh," was the only thing that left Tikki's mouth. This was definitely a predicament. No other Ladybug had ever had _this_ issue before.

"Don't you understand, Tikki?!" Marinette yelled in a panic. "It says Agreste! They _both_ say Agreste! And that can only mean one thing!"

Tikki nodded and remembered the time Marinette theorized that Gabriel Agreste was Hawkmoth. It was all suddenly clear to her and Tikki could only imagine what was going through Marinette's head.

"Yeah," Tikki replied. "I guess that-"

 _"Adrien Agreste is my soulmate_ and _my mortal enemy!"_ Marinette interrupted and launched into an all-out rant. "I know that he's not Hawkmoth because I've been with him when people have been akumatized and there's no way that he's the one akumatizing them but it probably means that he's going to reject me when I tell him how I feel because he's never going to accept that he's my soulmate he's not going to want to be my soulmate and that's going to make him my enemy no wonder he's been avoiding me so much lately he wants nothing to do with me he's probably afraid of me or something and what am I supposed to do now?!" Marinette fell back on her bed, arms spread wide as she made sobbing sounds. Tikki rolled her eyes. Five years and nothing ever changes with this girl. She moved to sit on Marinette's chest.

"Marinette, I'm sure that's not what's going to happen. Adrien isn't the only Agreste in Paris. There must be hundreds of them in France alone! And he would never deny his soulmate. He's very sweet!"

Marinette lifted her head to look Tikki in the eyes. "I know he's sweet. But then why has he been avoiding me so much lately? He can't even hold a conversation with me anymore. It's like me back in Collége...but worse!"

"Oh Marinette, I'm sure you have nothing to worry about. Now come on, school starts in ten minutes!"

"But I-wait, ten minutes? I'm gonna be late!" In one move, Marinette jumped down from her bed, grabbed her backpack, and ran downstairs. Tikki followed before jumping through the slight opening in Marinette's bag. Marinette yelled a hasty goodbye to her parents and ran out the door. Jumping around the corner, she called "Tikki, spots on!" and Ladybug swooped off to school.

* * *

It was the longest day of school Marinette had ever experienced. Adrien was in nearly all of her classes and the fact that they were in the same friend group didn't make the day any easier. Alya, Nino, and Adrien took Marinette out for a birthday lunch on them and Adrien wished Marinette a happy birthday that was accompanied by an awkward hug, but that was about all the direct interactions they really had that day. The four of them talked about Alya's graduation party tomorrow night and Alya complained about how the school needed to start making a bigger deal out of the event as a whole. Nino mentioned that his American cousin hated having to get up on a stage in front of hundreds of people to get a diploma and that he was glad they could just slide by with checking their grades and being on their way. Alya scoffed.

Adrien admitted to this being the first party his father actually let him go to unaccompanied that wasn't being held by one of his colleagues and said that he was just excited to be off on his own and starting University.

Marinette made them all promise to stay in contact once they were off on their own. The other three looked at her like she had lost her mind, but disregarded the obscurity of the comment and agreed anyways. Marinette tried to laugh it off with them, but looking at her best friends and her soulmate- _-her enemy_ -she didn't know what else to say.

Later that day, she showed Alya her wrists. Alya didn't know what to think. She told Marinette she'd get back to her with some theories before the party. Marinette told her not to bother. It was better to get it all over with on her own. The next day, she'd tell Adrien how she felt. Rip off the bandage. Just be done with it.

Ladybug and Chat Noir happened to run into each other that night. There was no akuma, no scheduled patrol for the day. They were both out to clear their heads. When they ran into each other on the Eiffel Tower, they didn't say a word. Just sat in comfortable silence, her head on his shoulder, his head on hers. They still couldn't reveal anything personal about themselves, no matter how much they wanted to. They both had their anxieties, but they'd learned over the years that each others' mere presence was enough to bring them each some sort of serenity. They parted at nearly midnight, feeling a vague sense of comfort.

It took her hours to fall asleep that night. She couldn't stop thinking.

The thinking carried on through the next morning, and until Alya's party, it didn't stop for a moment.

* * *

The party had been going on for about an hour. It was being held at Alya's house, and since her parents were already used to raising four kids, Alya, in her ever-convincing journalism-fueled argumentative state, was somehow able to convince them that hosting a couple dozen teenagers couldn't possibly be that much more of an addition to the madness-so long as they cleaned up the mess when the party was over.

Marinette was just finishing a conversation with Ivan and Myléne about how they were planning on maintaining their relationship long-distance.

"Ivan, I'm just impressed you got in. Good luck in Austria! We'll be here waiting for you when you get back!"

"Thanks, Marinette," Ivan said as he and Myléne began to walk away. Marinette smiled before hearing a soft voice come from behind her.

"Um, Marinette?" The black-haired graduate turned around swiftly at the sound of her name only to make immediate eye contact with a pair of beautiful emerald eyes that nearly made her heart stop short and beat right out of her chest at the same time. Her smile instantly disappeared as she tried to figure out her next move. She felt like she was 14 again, panicking at the sight of him. Although...there was something different this time. He wasn't smiling. He actually looked...a little nervous?

"Oh, uh, hey Adrien! Congrats on being first in class!" she said moving in for a hug. Adrien hugged back, but he squirmed a little under her hold. She let go.

"Thanks, Marinette. And congratulations on your scholarship. The International Fashion Academy is a huge accomplishment!"

"Oh, uh, thanks!" she said. "But I mean, it was your father who offered me the scholarship. I should really be thanking you guys for opportunity."

"Are you kidding? Adrien responded with a laugh. "My father is not a generous man. He would never offer something like this to anyone who didn't deserve it one hundred percent. You earned it, Marinette." His voice was considerably softer and more comfortable now, and Adrien smiled very warmly at the girl standing in front of him. She returned the gesture. Both of them suddenly took notice of the situation at the same moment and each let out an awkward chuckle.

"Heh, well uh, I really appreciate it either way. Is, uh, is there a reason you called my name though? Not that I don't enjoy talking to you in general, I was just wondering..."

Adrien's cheeks flushed. "Oh, uh, right."

A brief silence grew between them as they both waited for Adrien to say something, but he eventually cleared his throat and fixed his eyes back on hers-something that seemed very difficult for him to do in that moment.

"So, uh...you know how I've started wearing long sleeves lately?" Adrien asked. A comment that in any other context would have been wildly out of place, but given the circumstances of Marinette's miniature mental breakdown only one day prior, struck quite a nerve as she remembered her new magical tattoos on each of her own wrists. She began to look at Adrien's white sleeved button-down shirt-the long-sleeved equivalent of the one he wore the day she fell in love with him. Marinette remembered how he'd worn it to his own birthday party and had only worn long sleeves since. She never questioned it, just admired his new look. Now was the time for questioning it.

"Actually yeah. It's...a pretty nice look for you," she replied awkwardly.

"Well here's the thing," Adrien began to ramble. "There's actually a reason for that. And I'll admit I've been a little...you know, scared to talk about it, which is why I've kinda been avoiding you lately. Which I'm really sorry about! But we're starting University soon and I don't think I can wait any longer."

Marinette was mentally preparing herself. She'd heard of all the people whose soulmates didn't match up, the ones who were in love with someone else's soulmate, and the ones who were doomed to heartbreak. She knew she was one of them. She just wasn't ready to hear it.

"Oh?" It was supposed to sound like a question, but it came out more like she'd just been given a death sentence.

"Yeah," Adrien responded flatly. "Well, it kinda started on my eighteenth birthday. You know how you...you get those little...words on your wrist?"

Here it was. His soulmate was Chloe or Kagami or Lila or something and she was his enemy. She knew it. He's never going to speak to her again and she's never going to see him again and he's gonna marry someone better than her and she's gonna die alone and-

Adrien held out his wrist.

Marinette's heart stopped beating.

In bright red letters read an unmistakable last name.

 _'Dupain-Cheng'_

The hyphenated surname was incredibly original and Marinette wasn't sure there was another one in the world. But that's not even what got to her about the whole thing. It was the faded doodles surrounding the name. Hearts everywhere. He'd clearly tried to wash them off but to no avail. That meant that not only were they soulmates, but he _wanted_ them to be. He liked her. No. He _loved_ her.

Marinette didn't say a word. She didn't look away. She just rolled up her left sleeve and flipped her arm over, revealing the last name of the boy in front of her. He looked at it and smiled.

"Good," Adrien said, causing her to meet his gaze. "I'd hoped it was you."

Without another thought, Marinette moved in, wrapping her arms around his neck and pulling him close in a kiss. Adrien didn't hesitate for a moment, holding her closely by the waist and returning the gesture. Across the yard, Alya tapped Nino on the shoulder and pointed at the couple. The two of them high-fived before snapping a quick couple of pictures and returning to what they were doing. After a minute, Marinette and Adrien parted for air. Adrien chuckled.

"Guess now's a good time to give you this," he said, moving away a bit and reaching into his back pocket. He pulled out a small box that definitely had some sort of jewelry in it.

"Don't you dare get down on one knee," Marinette warned, nearly on the verge of tears. Adrien laughed.

"Oh fine, I won't. But happy birthday, Marinette," he said, opening the box to reveal a small silver heart-shaped necklace. "Wanna be my girlfriend?"

Marinette stared at the necklace. It was the most beautiful gift she'd ever been given-well, right next to the lucky charm he'd given her a few years back. Which was adorable, by the way, and was currently in her purse as it had been since the day she received it. She went in for another kiss that Adrien gladly returned, but it was much shorter this time due to the uncomfortable jewelry box slammed in between their stomachs.

Adrien took the necklace out of the box and looked at Marinette.

"May I?" he asked hopefully.

"Please do," she replied. Adrien unhooked the necklace and brought the two ends of the chain around Marinette's neck, rehooking it in the back and placing his hands on her shoulders.

"I love you, Marinette."

"I love you too, Adrien."

His hands ran up to her face and he pulled her in for one more kiss. It was long and full of love as they sunk into each other, fully aware of all of the party guests' eyes on their little scene and caring less than they'd ever not cared about anything before. When they finally parted again, there was a bit of applause from their surrounding friends. The couple blushed in sync, as they often were.

"By the way, let's not tell my father about this," Adrien whispered. Marinette nodded but gave him a questioning look. "He said I could attend IFA with you as long as I didn't do anything to disturb your studies. I swear, sometimes it's like he's my worst enemy."

Marinette giggled.

"Hey," Adrien said quietly, leaning in even closer. Marinette looked up at him. "I almost forgot. Check out the inscription." Adrien pulled the charm up with his left hand and showed it to Marinette. On the back of the heart, in beautiful cursive lettering, were two words.

 _'My Lady'_

"Just a nickname I picked up," Adrien winked. For the third time in a single conversation, Marinette felt her heart nearly explode. She looked at Adrien's right wrist. His hand still on her face, the sleeve had rolled down just enough for her to see what it said.

In small, black lettering read a single word.

 _'Agreste'_

Oh.

* * *

Sorry I couldn't fit the whole "Adrien thinks he's his own worst enemy" thing in there, I didn't want there to be TOO much going on. My belief is that on his 18th birthday, when Adrien looked at Plagg and told him he was his own worst enemy, Plagg responded by asking him "Are you sure Dupain-Cheng's not your enemy? You've always been pretty in love with yourself."

So yeah.

Thanks for reading! ^_^


End file.
